1. Field of the Invention
This invention is concerned with a method for reducing the amount of electrode wear in a matrix printer. More particularly, this invention is directed to a methodology for reducing electrode wear in an electrolytic printer by controlling pH of the reaction zone in which printing is to be effected.
2. Description of the Prior Art
It is well known that printing on a moving recording medium will cause some wear of the print electrodes. Mechanically induced degradation of the print electrodes is generally accepted as an unavoidable fact in such situations, a trade-off for increased thruput. Prior art attempts to minimize the need to frequently replace worn electrodes have centered on increased plating thicknesses of cover material for the electrodes or on arrangements to separate the electrodes and the recording medium during its movement through the printer.
In the case of electrolytic printing, however, the problem of print electrode degradation is compounded by the effects of the electrolytic and/or chemical reactions that occur at both the anode and cathode of the printer. More specifically, in certain types of electrolytic printing, either the anode is subjected to an excess of acid and the chemical wear that results therefrom or the cathode is exposed to degradation from an excess of base. The prior art approaches can alleviate this aspect of the electrode wear problem, but cannot prevent the electrodes' consumption. For example, the print electrodes can be plated or covered in some fashion with a layer of inert, tough wearing protection. However, protective materials that will satisfy all requirements for covering a print electrode in this operating environment are few in number and difficult to coat using ordinary methods. Further, such approaches are costly and/or reduce the thru-put rates and print quality of electrolytic printers. While there have been some attempts to avoid etching or corrosive effects in ink jet printers by neutralizing the inks used, such buffering would not be effective in electrolytic printers because mere neutralization of one reaction component would not solve the problem of electrochemically induced print electrode deterioration.